The present invention relates generally to the field of electronic data transfer, and more particularly to managing requests to a high utilization website.
The ability to effectively transfer electronic information over a data network is often highly dependent on the amount of resources available to the host that provides the information. For example, in the area of Internet content delivery, the ability of a network server to provide data (such as files, e-mail, and streaming media) to a large number of clients can be affected by the resource limitations of the host on which the server resides. Such resource limitations typically include, but are not limited to, network bandwidth, host processing power or CPU, available memory, file and/or socket descriptors, and disk input/output bandwidth. As the number of clients requesting files or other content from a particular server increases, one or more of these resources can eventually become exhausted.
Conventional network servers typically exhibit one or more of the following behaviors as their resources near exhaustion: (1) additional clients are completely denied access, either with a standard error message/protocol or simply through the inability to complete a transaction; (2) additional clients are served, but the performance for all clients accessing the host degrades, often creating a “snowball” effect whereby performance eventually reaches zero for all clients as resources are completely exhausted; and/or (3) the host is shut down or “crashes” because a key resource is exhausted. These behaviors are undesirable for client users as well as for hosts, and often impair the ability of any user to receive content during peak demand periods. This impairment is exacerbated by the fact that conventional clients, such as conventional web browsers, are programmed to continually retry their requests, which puts additional strain on the network server and can lead to further resource exhaustion.